Rectifier for alternating current



Dec. 3, 1929. c. E. OGDEN RECTIFIER FOR ALTERNATiNG CURRENT Filed June 26, 1928 Patented Dec. 3, 1929 UNITED STATES PATENT- OFFICE CLARENCE E. OGDEN, CINCINNATI, OHIO, ASSIGNOR TO THE KODEL RADIO CORPORATION A. CORPORATION OF OHIO RECTIFIER FOR ALTERNATING CURRENT Application filed June 26, 1928. Serial No. 288,327.

My invention relates to rectifiers for alterhating current, and has particular reference to rectifiers of the dry metallic type.

In the use of dry metallic rectifiers, as fo'r instance, copper oxide rectifiers, it is found that when heated beyond a certain tempera ture, the discs deteriorate in value, the resistance increasing to such a degree as mate rially to interfere with the proper current flow for which the rectifier is designed.

The principal object of the present invention is to provide means whereby when the rectifying discs approach a dangerous temperature, the source of current supply is cut off automatically, thus relieving the discs and permitting the same to cool to the proper temperature, after which the current is again automatically connected and the desiredfiow resumed.

Other objects of the invention will appear from the following detailed description.

In the drawings:

Figure 1 is an elevation of a rectifier constructed in accordance with this invention.

Figure 2 is a section of said rectifier.-

Figures 3 and 4 are elevations of a modified structure.

Figure 5 is a diagrammatic view of the rectifier and circuits.

The numeral 1 indicates copper rectifier discs, the same being provided, 1n accordance with common construction, with layers of copper oxide 2-2 and copper film terminals 33. Contact is made with the films 3--3 by :5 means of plates 4, the same being of corrugated construction, as shown in Figure 2, to provide fines 5 for cooling purposes. Arranged to make contact with plates 4 is a strip of thermostatic metal 6, adapted when 43 in its normal or cool condition, to make contact with one terminal 7 in the current load. When the discs become heated through operation they heat the thermostatic metal strip 6, which is of a nature to deflect, as shown in 45 broken lines in Figure 1, so as to open the cricuit before a dangerous disc temperature is attained.

In Figures 3 and 4 I have shown a stack 8 of rectifier discs, the same being assembled in the usual manner and disposed under a.

canopy 9. The strip of thermostatic metal 10 is arranged to make contact with terminal 7 when the strip is at normal operating temperature; when heated, by the accumulation of heat under the canopy, said heat arising from the discs under operation, the metal is deflected to the position shown in broken lines in Figure 3, and the current is automatically opened. i

From the foregoing description the nature and purpose of the present invention will be fully apparent to those skilled in the art to which the same appertains.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination with a rectifier of the character mentioned, a canopy over said rectifier arranged to accumulate heat therefrom, and a thermostatic current control under said canopy, said control'being arranged to open the circuit when heated beyond normal op-",' erating temperature. 5

2. In combination with a rectifier of the character mentioned, a canopy. over said rectifier arranged to accumulate heat therefrom, a conductor constructed of thermostatic metal under said canopy, said conductor being adapted to open the circuit when heated beyond normal operating temperature.

CLARENCE E. OGDEN. 

